The present invention relates to a lift used for maintenance of vehicles, which includes an elevation mechanism for ascending and descending between a floor level and a predetermined height and a drive-on-plate for supporting the body of a mounted vehicle. More specifically, the invention pertains to a movable one-post lift which can be used in a narrow space.
Several types of stationary and movable lifts with a drive-on-plate have been proposed for maintenance of vehicles. Commonly used one-post lifts, which support the load with a single beam, are stationary type and fixed to the floor with anchor bolts. Movable lifts are, however, favorably applied to simple maintenance facilities in tire stands and car parts dealers or temporary maintenance facilities.
One example of such movable lifts is disclosed in Japanese Patent Publication Gazette No. Sho-46-9015, including: a support post mounted on one end of a base with transport wheels; a cantilever beam with a pair of vehicle supports which is thrust under a vehicle and lifts and lowers the body of the vehicle along the support post by an elevation mechanism. Here one of the vehicle supports on the cantilever beam may be slidable as shown in FIG. 16 to adjust the distance between the supports.
In this example, the cantilever beam is horizontally thrust under a stationary vehicle, and a free space corresponding to the length of the cantilever beam sufficient for supporting a mounted vehicle, that is, movable space of the cantilever beam, is thereby required on the vehicle side. Accordingly the movable lifts of such structure are not practically used in narrow garages and limited spaces. Furthermore the long cantilever beam hinders smooth transport and storage of the movable lift.
In the lift with the adjusting mechanism, the vehicle support is slidable only when the cantilever beam is placed over the base to avoid undesirable contact of the drive-on-plate with the base. The adjusting mechanism may also cause rattling and squeaking. Another disadvantage of this example is its troublesome operation; that is, a vehicle should be fixed to the lift with the cantilever beam placed under the vehicle.
In another prior art structure disclosed in Japanese Patent Publication Gazette No. Sho-56-4480, transport wheels are protrudent from the bottom of a base only by a small length to improve stability in stationary conditions. This system, however, does not attain sufficient stableness in lift-up position nor ensure smooth movement of the lift on a rough floor surface. The wheels are disposed on front and rear ends of the base to make the radius of gyration undesirably large.
In a conventional structure, a vehicle is lifted up with all the wheels placed on the drive-on-plate. Free wheel structure is, however, typically applied, in which wheels of the vehicle are not mounted on the drive-on-plate but are maintained at predetermined positions over the drive-on-plate, thereby being freely detachable, while the body of the vehicle is securely supported. Since the drive-on-plate is higher by its thickness than the floor level, a riding plate or plates are generally used for easy riding of wheels on or over the drive-on-plate. The riding plate may detachably be arranged or be fixed to both ends of the drive-on-plate in alignment.
Detachable riding plates 23 shown in FIG. 15A are placed next to a drive-on-plate 15(16) every time when a vehicle M is mounted on the lift, and are cleared away after the vehicle M is lifted up. When riding plates 23 are fixed to the drive-on-plate 15(16) in free wheel structure as shown in FIG. 15B, on the other hand, the plates 23 may prevent smooth detachment of wheels 25 of the vehicle M. Accordingly, an effective length L2 of the drive-on-plate 15(16) directly in contact with the body of the vehicle M is determined to be small.